Final answer:
To make a 1:8 dilution of chemical Y, you will need 2800 milliliters of diluent.
Step-by-step explanation:
To make a 1:8 dilution of chemical Y, you need to mix 1 part of the chemical with 8 parts of a diluent. Since you have 350 milliliters of chemical Y, you will need to add 8 times this amount of diluent.
350 milliliters x 8 = 2800 milliliters
Therefore, option b) 2800 milliliters is the correct answer.